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Centaurus A (Cen A) is the nearest radio galaxy discovered as a very-high-energy (VHE; 100 GeV-100 TeV) $\gamma$-ray source by the High Energy Stereoscopic System (H.E.S.S.). It is a faint VHE $\gamma$-ray emitter, though its VHE flux…

High Energy Astrophysical Phenomena · Physics 2018-11-14 H. E. S. S. Collaboration , H. Abdalla , A. Abramowski , F. Aharonian , F. Ait Benkhali , E. O. Angüner , M. Arakawa , C. Armand , M. Arrieta , M. Backes , A. Balzer , M. Barnard , Y. Becherini , J. Becker Tjus , D. Berge , S. Bernhard , K. Bernlöhr , R. Blackwell , M. Böttcher , C. Boisson , J. Bolmont , S. Bonnefoy , P. Bordas , J. Bregeon , F. Brun , P. Brun , M. Bryan , M. Büchele , T. Bulik , M. Capasso , S. Caroff , A. Carosi , S. Casanova , M. Cerruti , N. Chakraborty , R. C. G. Chaves , A. Chen , J. Chevalier , S. Colafrancesco , B. Condon , J. Conrad , I. D. Davids , J. Decock , C. Deil , J. Devin , P. deWilt , L. Dirson , A. Djannati-Ataï , A. Donath , L. O'C. Drury , J. Dyks , T. Edwards , K. Egberts , G. Emery , J. -P. Ernenwein , S. Eschbach , C. Farnier , S. Fegan , M. V. Fernandes , A. Fiasson , G. Fontaine , S. Funk , M. Füßling , S. Gabici , Y. A. Gallant , T. Garrigoux , F. Gaté , G. Giavitto , D. Glawion , J. F. Glicenstein , D. Gottschall , M. -H. Grondin , J. Hahn , M. Haupt , J. Hawkes , G. Heinzelmann , G. Henri , G. Hermann , J. A. Hinton , W. Hofmann , C. Hoischen , T. L. Holch , M. Holler , D. Horns , A. Ivascenko , H. Iwasaki , A. Jacholkowska , M. Jamrozy , D. Jankowsky , F. Jankowsky , M. Jingo , L. Jouvin , I. Jung-Richardt , M. A. Kastendieck , K. Katarzyński , M. Katsuragawa , U. Katz , D. Kerszberg , D. Khangulyan , B. Khélifi , J. King , S. Klepser , D. Klochkov , W. Kluźniak , Nu. Komin , K. Kosack , S. Krakau , M. Kraus , P. P. Krüger , H. Laffon , G. Lamanna , J. Lau , J. Lefaucheur , A. Lemière , M. Lemoine-Goumard , J. -P. Lenain , E. Leser , T. Lohse , M. Lorentz , R. Liu , R. López-Coto , I. Lypova , D. Malyshev , V. Marandon , A. Marcowith , C. Mariaud , R. Marx , G. Maurin , N. Maxted , M. Mayer , P. J. Meintjes , M. Meyer , A. M. W. Mitchell , R. Moderski , M. Mohamed , L. Mohrmann , K. Morå , E. Moulin , T. Murach , S. Nakashima , M. de Naurois , H. Ndiyavala , F. Niederwanger , J. Niemiec , L. Oakes , P. O'Brien , H. Odaka , S. Ohm , M. Ostrowski , I. Oya , M. Padovani , M. Panter , R. D. Parsons , N. W. Pekeur , G. Pelletier , C. Perennes , P. -O. Petrucci , B. Peyaud , Q. Piel , S. Pita , V. Poireau , D. A. Prokhorov , H. Prokoph , G. Pühlhofer , M. Punch , A. Quirrenbach , S. Raab , R. Rauth , A. Reimer , O. Reimer , M. Renaud , R. de los Reyes , F. Rieger , L. Rinchiuso , C. Romoli , G. Rowell , B. Rudak , C. B. Rulten , V. Sahakian , S. Saito , D. A. Sanchez , A. Santangelo , M. Sasaki , R. Schlickeiser , F. Schüssler , A. Schulz , U. Schwanke , S. Schwemmer , M. Seglar-Arroyo , A. S. Seyffert , N. Shafi , I. Shilon , K. Shiningayamwe. R. Simoni , H. Sol , F. Spanier , M. Spir-Jacob , Ł. Stawarz , R. Steenkamp , C. Stegmann , C. Steppa , I. Sushch , T. Takahashi , J. -P. Tavernet , T. Tavernier , A. M. Taylor , R. Terrier , L. Tibaldo , D. Tiziani , M. Tluczykont , C. Trichard , M. Tsirou , N. Tsuji , R. Tuffs , Y. Uchiyama , D. J. van der Walt , C. van Eldik , C. van Rensburg , B. van Soelen , G. Vasileiadis , J. Veh , C. Venter , A. Viana , P. Vincent , J. Vink , F. Voisin , H. J. Völk , T. Vuillaume , Z. Wadiasingh , S. J. Wagner , P. Wagner , R. M. Wagner , R. White , A. Wierzcholska , P. Willmann , A. Wörnlein , D. Wouters , R. Yang , D. Zaborov , M. Zacharias , R. Zanin , A. A. Zdziarski , A. Zech , F. Zefi , A. Ziegler , J. Zorn , N. Żywucka , Fermi-LAT collaboration , J. D. Magill , S. Buson , C. C. Cheung , J. S. Perkins , Y. Tanaka

We report the discovery of a statistically significant hardening in the Fermi-LAT $\gamma$-ray spectrum of Centaurus A's core, with the spectral index hardening from $\Gamma_{1}=2.73 \pm 0.02$ to $\Gamma_{1}=2.29 \pm 0.07$ at a break energy…

High Energy Astrophysical Phenomena · Physics 2017-11-16 Anthony M. Brown , Celine Bœhm , Jamie Graham , Thomas Lacroix , Paula Chadwick , Joe Silk

A high-energy component in the radio galaxy Centaurus A was reported after analyzing four years of Fermi data. The spectrum of this component is described by means of a broken power law with a break energy of 4 GeV and, below and above…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Nissim Fraija

We report the discovery of faint very high energy (VHE, E>100 GeV) gamma-ray emission from the radio galaxy Centaurus A in observations performed with the H.E.S.S. experiment, an imaging atmospheric Cherenkov telescope array consisting of…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-17 HESS Collaboration , F. Aharonian

We report the discovery of faint very high energy (VHE, E > 100 GeV) gamma-ray emission from the radio galaxy Centaurus A in deep observations performed with the H.E.S.S. experiment. A signal with a statistical significance of 5.0 sigma is…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 M. Raue , J. -P. Lenain , F. A. Aharonian , Y. Becherini , C. Boisson , A. -C. Clapson , L. Costamante , L. Gerard , C. Medina , M. de Naurois , M. Punch , F. Rieger , H. Sol , L. Stawarz , A. Zech

The association of at least a dozen ultrahigh-energy cosmic-ray (UHECR) events with energy $\gtrsim 55$ EeV detected by the Pierre Auger Observatory (PAO) from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of…

High Energy Astrophysical Phenomena · Physics 2018-05-02 Jagdish C. Joshi , Luis Salvador Miranda , Soebur Razzaque , Lili Yang

The radio galaxy Cen A has been detected all the way up to the TeV energy range. This raises the question about the dominant emission mechanisms in the high-energy domain. Spectral analysis allows us to put constraints on the possible…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 V. Beckmann , P. Jean , P. Lubinski , S. Soldi , R. Terrier

Fermi LAT has detected gamma ray emissions from the core of Cen A. More recently, a new component in the gamma ray spectrum from the core has been reported in the energy range of 4 GeV to tens of GeV. We show that the new component and the…

High Energy Astrophysical Phenomena · Physics 2014-05-02 Esha Kundu , Nayantara Gupta

Centaurus A (Cen A) is the nearest radio-loud AGN and is detected from radio to very high energy gamma-rays. Its nuclear spectral energy distribution (SED) shows a double-peak feature, which is well explained by the leptonic synchrotron +…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Sarira Sahu , Bing Zhang , Nissim Fraija

Centaurus A, at a distance of less than 4 Mpc, is the nearest radio-loud AGN. Its emission is detected from radio to very-high energy gamma-rays. Despite the fact that Cen A is one of the best studied extragalactic objects the origin of its…

High Energy Astrophysical Phenomena · Physics 2015-05-14 H. Steinle

Centaurus A is the nearest radio-loud AGN and is detected from radio to very high energy gamma-rays. Its nuclear spectral energy distribution shows two peaks, one in the far-infrared band and another at about 150 keV. By assuming the second…

High Energy Physics - Phenomenology · Physics 2010-07-06 Nissim Fraija , Sarira Sahu , Bing Zhang

The nearest active radio galaxy Centaurus (Cen) A is a gamma-ray emitter in GeV to TeV energy scale. The High Energy Stereoscopic System (H.E.S.S.) and non-simultaneous Fermi-LAT observation indicate an unusual spectral hardening above few…

High Energy Astrophysical Phenomena · Physics 2021-02-02 Prabir Banik , Arunava Bhadra , Abhijit Bhattacharyya

Centaurus A, the closest active galaxy, has been detected from radio to high-energy gamma-rays. The synchrotron radiation by extremely high energy protons may be a suitable mechanism to explain the MeV to GeV emission detected by the…

High Energy Astrophysical Phenomena · Physics 2015-05-13 M. Orellana , G. E. Romero

Aims: We investigate the role of the second synchrotron self-Compton (SSC) photon generation to the multiwavelength emission from the compact regions of sources that are characterized as misaligned blazars. For this, we focus on the nearest…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Maria Petropoulou , Eva Lefa , Stavros Dimitrakoudis , Apostolos Mastichiadis

The question of the origin of the hard X-ray/soft gamma-ray emission in Centaurus A (Cen A) persists despite decades of observations. Results from X-ray instruments suggest a jet origin since the implied electron temperature (kT_e) would…

High Energy Astrophysical Phenomena · Physics 2023-10-03 James Rodi , E. Jourdain , M. Molina , J. -P. Roques

Motivated by the detection of a hardening in the gamma-ray spectrum of the radio galaxy Centaurus A, we have analysed ~10 years of Fermi-LAT observations of 26 radio galaxies to search for similar spectral features. We find that the…

High Energy Astrophysical Phenomena · Physics 2020-01-14 Cameron B. Rulten , Anthony M. Brown , Paula M. Chadwick

We revisit the average hard X-ray spectrum from the AGN of Centaurus A (Cen A) using ten years worth of observations with INTEGRAL SPI. This source has the highest flux observed from any AGN in the SPI bandpass (23 keV--8 MeV). The 10 year…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Mark J. Burke , Elisabeth Jourdain , Jean-Pierre Roques , Daniel A. Evans

The Rossi X-ray Timing Explorer made a short (10 ks) observation of the radio galaxy Centaurus A on 14 August 1996. Analysis of the combined 2.5-240 keV spectrum has revealed a heavily absorbed(NH=9.42+/-0.24 e22 cm-2) primary power law…

Centaurus A (Cen~A) is the nearest active radio galaxy, which has kiloparsec (kpc) scale jets and {giant lobes detected by various instruments in radio and X-ray frequency ranges}. The $Fermi$--Large Area Telescope and High Energy…

High Energy Astrophysical Phenomena · Physics 2019-08-07 Kazuhisa Tanada , Jun Kataoka , Yoshiyuki Inoue

The radio galaxy Centaurus A was observed by the BeppoSAX satellite five times from 1997 to 2000. From July 6 1999 to August 17 1999, the source was also simultaneously pointed by COMPTEL on-board of the satellite CGRO. Centaurus A has a…

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